The 'glass ceiling' is a metaphor used to describe a kind of barrier that can stop some people getting to a higher point in their career. It usually applies to women and people from minority backgrounds. If a person hits a glass ceiling, they may be very qualified and have lots of experience, but they might find it hard to get promoted or get to the top of their field. This barrier is like a glass ceiling because it is hard to see or even to know that it is there, but it can stop someone from getting to the top.